Observations on 193 Harvard
plates confirm that RU Sex is an RR Lyrae Variable. A period search by discrete
Fourier transform found candidate periods near 0.26, 0.35, and 0.54 day.
Analysis of the times of maxima and phased light curves indicates that the best
period is 0.3502323 day. The periods near 0.26 and 0.54 day are aliases
differing in frequency by one cycle per sidereal day.